JP2009294065A - Structure of radiation indicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation indicator structure for inspecting whether sterilization processing by the use of radiation has been carried out. <P>SOLUTION: This radiation indicator structure has a polymer resin film having transparency, a radiation indicator layer formed on the rear face of the polymer resin film and composed of radiation discoloration paint, and a base layer laminated integrally with the polymer resin film while interposing the radiation indicator layer in between and composed of synthetic resin or paper. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement of a radiation indicator structure for detecting radiation irradiation used in various fields in the industry.

In recent years, radiation irradiation has been used in various fields such as radiation sterilization, industry, agriculture, and consumer goods.
For example, when food or medical equipment is placed in a resin film or packaging container and sterilized or sterilized by irradiation with gamma rays or the like, as a means for confirming whether radiation has been reliably applied, As shown in FIG. 3, a paper label 20 is used in which a pressure-sensitive adhesive layer 25 is provided on the back side of a base material layer 24 made of paper, and a radiation indicator layer 23 is applied on the front side. Is affixed to a container or bag, and for example, a method of confirming the completion of sterilization is known by changing the color of the portion from yellow before irradiation to red after irradiation.
In addition, for example, in the radiation dosimeter shown in Japanese Patent Publication No. 6-72929, on a substrate made of a polymer resin molded product, a polymer containing an acetate group, a dye that changes color due to a change in pH, and methane, ethane, or propane Or the structure etc. which formed the radiation indicator layer containing the bromine compound which substituted at least 1 or more of hydrogen of the butane derivative with the bromine are disclosed.

In the conventional examples, since the radiation indicator layer is exposed on the surface and is in contact with the outside air, the color of the indicator layer is gradually changed even if it is not irradiated with radiation if it is easily affected by ultraviolet rays. There is a risk that.
In addition, since it is affected by the surrounding atmosphere such as the weather and the outside air, there is a possibility that the color gradually returns to the original state after irradiation with radiation, and there is a problem that reliability as an indicator is lacking.
Moreover, when taking the form of a label, it may peel off from a package etc. or articles | goods, and may forget to stick.
Furthermore, when sticking to individual packaging, it is necessary to stick by hand one by one. Is often affixed on a label for printing.
Japanese Patent Publication No. 6-72929

  The present invention was devised in view of the above circumstances, and its main problem is to provide a radiation sterilization indicator film capable of enhancing the reliability as an indicator without exposing the radiation indicator layer to the surface. It is in.

The present invention has been developed to solve the above-described problems. In the invention of claim 1,
A cover layer made of a polymer resin film having transparency;
A radiation indicator layer made of a radiation-changing paint formed on the back surface of the polymer resin film;
A radiation indicator structure comprising a base material layer made of synthetic resin or paper and laminated integrally with the polymer resin film with the radiation indicator layer interposed therebetween.

In the invention of claim 2,
The base material layer is made of a sealant film, laminated on a polymer resin film, and can be used as a packaging film.
In the invention of claim 3,
The base material layer is made of paper, and an adhesive layer is formed on the back surface of the paper,
It can be used as a label.
In the invention of claim 4,
The radiation indicator layer is formed by printing such as gravure printing on the back surface of the polymer resin film with a radiation-changing paint.

According to this invention, since the radiation indicator layer is covered with the cover layer of the transparent polymer resin film, the paint layer does not come into contact with the outside air, and is not easily affected by the weather or the atmosphere of the outside air. effective.
If a material having an ultraviolet ray or other predetermined light blocking function is used for the cover layer of the polymer resin film, it is possible to make the radiation indicator layer less susceptible to discoloration due to ultraviolet rays or other adverse effects on the radiation indicator layer.
In addition, since the radiation indicator layer is printed on the cover layer itself, when used as a packaging film sheet or packaging container, it is not necessary to affix a radiation indicator label separately from the packaging, improving workability. Costs can be reduced, and there is no problem of forgetting to stick.

In the present invention, a radiation indicator layer is formed on the back surface of a cover layer made of a transparent polymer resin film by printing or the like, and a base material layer is laminated so as to expose the radiation indicator layer on the surface. Built-in without improving the reliability as an indicator.
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, the packaging film 1 which has a radiation indicator function is shown as Example 1 of a radiation indicator structure.
This packaging film 1 has a cover layer 2 made of a polymer resin film having transparency.
A radiation indicator layer 3 is formed on one surface of the cover layer 2 by printing a radiation-changing paint.
In this embodiment, gravure printing is used as printing, but other known printing methods may be used.

And the packaging film 1 is formed by laminating the sealant film 4 as a base material layer on the surface on which the radiation indicator layer 3 is formed.
In this embodiment, the radiation indicator layer 3 extends as an example along the longitudinal direction of the packaging film 1 and is formed continuously or intermittently at regular intervals.

  And the packaging film 1 is cut | disconnected in a transversal direction in a predetermined part, and the radiation indicator layer 3 is always arrange | positioned at the parted film, However, In this invention, it is limited to the said structure. It can be made into arbitrary shapes and numbers.

Next, as the cover layer 2, a known material of a polymer resin film can be appropriately selected in consideration of conditions that can be adhered to a radiation-discoloring paint and do not adversely affect performance and are compatible with radiation sterilization treatment. It is preferable to use mainly the following materials.
That is, for example, polyethylene terephthalate (PET), polyamide (PA), polyethylene (PE), polypropylene (PP), polyacrylonitrile (PAN), polystyrene (PS), polyvinyl chloride (PVC), polycarbonate (PC), poly Examples thereof include methyl methacrylate (PMMA) and polyurethane (PU).

Similarly, the sealant film 4 can be appropriately selected, but it is preferable to mainly use the following materials.
That is, for example, polyethylene (PE), polypropylene (PP), polyacrylonitrile (PAN), polyethylene terephthalate (PET), and the like.

For the radiation indicator layer 3, for example, a known radiation discoloration paint described in Patent Document 1 can be used.
That is, a radiation discoloration coating material is a bromine compound or chlorine substituted with bromine or chlorine at least one of a polymer containing an acetic acid group in the molecule, a dye that changes color due to pH change, and hydrogen of methane, ethane, propane, or butane. Contains compounds.

If a processing target is packaged using the packaging film 1 configured as described above, an indicator is attached to each package, and a process of attaching an indicator label separately is not necessary.
For example, conventionally, an indicator label is often attached only to a collective package of medical-related products.

In that case, if the collective package is separated into individual packages at a medical site or the like, it cannot be confirmed whether the sterilization process has been performed at the individual package level.
However, if the film sheet of a present Example is used, since the radiation indicator layer 3 is provided in all the individual packages, the presence or absence of a sterilization process can be confirmed separately.

Further, since the radiation indicator layer 3 is sandwiched between the cover layer 2 and the sealant film 4 and does not come into contact with the outside air, it is extremely less affected by the atmosphere, and the reliability as an indicator is high.
Moreover, if the cover layer 2 is made of a film having ultraviolet cut (prevention) functionality, the influence of ultraviolet rays on the radiation indicator layer 3 can be reduced.

In the above embodiment, the case where the radiation indicator structure is applied to the packaging film is exemplified. However, in the present invention, the base material layer is a synthetic resin material having a thickness larger than that of the film, and this may be used as a molded packaging container. Good.
In this case, the description is omitted because it conforms to the first embodiment.

Next, FIG. 2 shows a label 10 having a radiation indicator function as a second embodiment of the radiation indicator structure.
This label 10 has a cover layer 12 made of a polymer resin film having transparency.
Since the structure which forms the radiation indicator layer 13 by carrying out gravure printing of the radiation discoloration coating material on one surface of this cover layer 12 is the same as that of the said Example 1, the description is abbreviate | omitted.

And the label base material layer 14 which consists of paper or a polymer resin film is stuck on the surface in which the said radiation indicator layer 13 was formed, and is laminated | stacked.
The thickness of the paper or the polymer resin film is a thickness that can function as the label 10 and can be appropriately set depending on the application.
The polymer resin film used for the label base layer 14 may be the same as or different from the cover layer 12.
Further, the lamination method is not particularly limited.

An adhesive material layer 15 is provided on the back surface of the label base material layer 14 to form the label 10.
Here, a release sheet (not shown) may be provided on the adhesive material layer 15, and it may be peeled off during use to expose the adhesive material layer 15 for use.

Similarly to the packaging sheet 1, the label 10 of Example 2 is not exposed to the outside air because the radiation discoloration paint is sandwiched between the transparent cover layer 12 and the label base material layer 14 and is not exposed to the outside air. Less susceptible to the atmosphere.
Further, by selecting a material having a function of cutting a predetermined light ray such as an ultraviolet ray for the polymer resin film as in the first embodiment, it is possible to make the polymer resin film less susceptible to the influence of the light ray, and as a radiation indicator. Can increase the sex.

The label 10 can be directly attached to a package on which an indicator is not printed in advance or an article to be processed.
Here, the label 10 is not limited to an independent structure, but may be wound in a roll shape, and may be used in such a manner that the usage amount is drawn out and used as necessary.
Moreover, in each said Example, although the three-layer structure which pinched | interposed the indicator layer was illustrated, you may interpose another functional film in an intermediate | middle layer.

In the above embodiment, the radiation indicator layer is printed on the back surface of the cover layer. However, the radiation indicator layer only needs to be formed on the back surface side of the transparent cover layer. The base material layer and the cover layer may be integrally formed by lamination or the like.
Furthermore, although the case where the cover layer and the base material layer are one layer was illustrated, it is good also as a multilayer structure in the range which does not impair those functions.
Further, the radiation irradiation detected in the present invention is not limited to medical sterilization, but covers all widely used industrial products such as food packaging materials, other sterilization, and plastic modification.
In addition, various design changes can be made without departing from the scope of the present invention.

1 is a cross-sectional view of a packaging film having a radiation indicator function of Example 1. FIG. It is sectional drawing of the label which has a radiation indicator function of Example 2. FIG. It is sectional drawing of the conventional label.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Packaging film which has a radiation indicator function 2 Cover layer 3 Radiation indicator layer 4 Base material layer 10 Label 12 which has a radiation indicator function Cover layer 13 Radiation indicator layer 14 Label base material layer 15 Adhesive material layer 20 Conventional which has a radiation indicator function Paper label 23 Radiation indicator layer 24 Base material layer 25 Adhesive layer

Claims (4)

A cover layer made of a polymer resin film having transparency;
A radiation indicator layer made of a radiation-changing paint formed on the back surface of the polymer resin film;
A radiation indicator structure comprising a base material layer made of synthetic resin or paper laminated integrally with the polymer resin film with the radiation indicator layer interposed therebetween.   The radiation indicator structure according to claim 1, wherein the base material layer is made of a sealant film, laminated to a polymer resin film, and can be used as a packaging film. The base material layer is made of paper, and an adhesive layer is formed on the back surface of the paper,
The radiation indicator structure according to claim 1, wherein the radiation indicator structure can be used as a label.   The radiation indicator structure according to any one of claims 1 to 3, wherein the radiation indicator layer is formed by printing such as gravure printing on the back surface of the polymer resin film with a radiation discoloration paint.

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